Magnetic field switches, such as Hall effect switches, are a type of magnetic sensor with a digital output that toggles from high to low and from low to high when certain levels of the magnetic field intensity are sensed. Such switches are often used for proximity sensing, and the magnetic field-versus-output voltage characteristics include a certain amount of hysteresis in order to provide noise immunity.
The output behavior of these switches can be unipolar, bipolar or omnipolar. In unipolar switches, the output is dependent upon both the magnitude of the field and the polarity. For some applications, however, dependence on the polarity is not desired, and omnipolar switches are therefore desired. Conventional omnipolar switches use, for example, two cross-coupled hysteresis comparators with digital processing or other solutions typically requiring multi-step evaluation to create omnipolar behavior. For some applications, such solutions are not appropriate because they are too slow or exhibit other undesirable characteristics.
Therefore, there is a need for improved omnipolar magnetic field switches.